The Distribution of European Corn Borer Larvae Pyrausta nubilalis (Hbn.), in Field Corn

Abstract

For many years research entomologists have realized that insect populations have a tendency to be heterogeneously distributed. This heterogeneity is present in the distribution of larval populations of the European corn borer, Pyrausta nubilalis (Hbni.). To the research entomologist conducting experiments on larvae of the corn borer an understanding of this heterogeneity, or spottiness, in the distribution of the insect would be of help in the design of experiments. Distributions may be fitted for either one of two reasons: (a) to find a transformation in order to use normal theory, for example, in performing an analysis of variance (here it does not matter if the form of distribution fitted is particularly accurate); or (b) in relating observed counts to some theory of population growth or spread (requiring forms of distributions that are biologically significant.) The purpose of this paper is to report the results of fitting three biologically significant statistical models, the negative binomial, Neyman's type A and the Poisson binomial to entomological field data.